Fiber optic connectors, also known as terminations, connect two ends of fiber optic cables. The connector features a ferrule, the connector end piece that holds and secures the fiber and aligns it for light. In fiber-optic communication, a single-mode optical fiber, also known as fundamental- or mono-mode, is an optical fiber designed to carry only a single mode of light - the transverse mode. A single. Dual fiber transceivers use two fibers, giving more speed and stability. They are great for city networks or 5G systems. 25 mm ferrule, which makes it perfect for snap-in, high-density, compact applications.